NC0000396_Ash basin piping - Inspection project_20150319

DUKE
ENERGY,
PROGRESS
March 19, 2015
Mr. Jeff Poupart
North Carolina Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699 -1617
Subject: Duke Energy Progress, Inc.
Asheville Steam Electric Plant
Ash basin piping — Inspection project
NC0000396
Buncombe County
Dear Mr. Poupart:
Environmental Services
Duke Energy
526 South Church Street
Charlotte, NC 28202
Mailing Address
EC13K / P.O. Box 1006
Charlotte, NC 28201 -1006
RECEIVEDlDENROWR
MAR 2 0 2015
Water Quality
Permitting Sectior
As we discussed with you during a recent meeting, Duke Energy (Duke) needs to conduct a
video inspection of a section of HDPE pipe leading from the small open water area of the 1964
ash basin (hereinafter referred to as the "Duck pond ") to the outlet piping leading to NPDES
permitted outfall 001 at the subject facility. This section of pipe is approximately 50 feet in
length and this video inspection is intended to be used as a tool to detect any structural concerns
with the section of pipe.
To facilitate this work, the water level in the "Duck pond" must be lowered by two feet so this
section of pipe can be inspected. Recall that the water in the "Duck Pond" is released to outfall
001 as part of routine operations. Duke intends to use a floating intake on the pump and slowly
lower the water in the "Duck pond" over a five day period of time to lessen the potential for re-
entrainment of any settled solids. This change in water level equates to a short term increase of
approximately 0.16 MGD. All flow will go through the final outfall point and be included in
routine sampling. Daily wastewater flow from generation operations will be treated as normal in
the rim ditch and routed from the rim ditch directly to the outlet pipe leading to outfall 001 during
this temporary period of lowering the "Duck pond ".
Upon lowering of the water level in the "Duck pond" a video camera will be inserted into the
pipe to perform the inspection. We anticipate that the video inspection itself should be started
and completed in one day. After the video inspection, the "Duck pond" will be allowed to return
to its original level and the flow to outfall 001 will decrease for some time until the water returns
to its original level.
Chemical characterization of the water in the "Duck pond" was submitted to your office dated
February 4, 2015. If there are additional questions about the characteristics of this water, we
would refer you to the facility's submitted Discharge monitoring reports for outfall 001. For

Mr. Jeff Poupart
March 19, 2015
Asheville pipe inspection
Page 2 of 3
additional information, an aerial map is enclosed that identifies the location of this proposed
activity.
As there is no change to the final release point of this water and no changes to the characteristics
of this water, Duke Energy believes that this proposed short term activity will not require
NPDES permit modification or other water permitting actions. If you concur, we would
appreciate your written (email) acknowledgement of approval to proceed at your earliest
opportunity. If you have any questions or concerns regarding our proposed course of action,
please contact Mr. Shannon Langley at (919) 546 -2439 or by email at shannon.langley @duke-
energy.com.
Sincerely,
q4 1/0/
Richard E. Baker, Jr., P.E., PMP
Director, Environmental Programs, EHS CCP
Enclosure
RB /esl
cc: Laurie Moorhead w /enclosure
Shannon Langley w /enclosure— NCRH 14

Mr. Jeff Poupart
March 19, 2015
Asheville pipe inspection
Page 3 of 3
Attachment to Letter to Jeff Poupart
Ash Basin HDPE piping — Inspection project
Asheville Plant area of HDPE pipe to be inspected shown in RED